1,720,954 research outputs found
No evidence for cicadas’ implication in Xylella fastidiosa epidemiology
Full text linkCicadas are prominent insects in the Mediterranean basin environments, including in olive orchards. The bacte- rium Xylella fastidiosa is a xylem-limited vector-borne plant pathogen that was introduced into southern Italy, causing significant losses of olive trees. Cicadas are xylem-sap feeders and potential vectors of X. fastidiosa; however, knowledge of their role in the transmission of this bacterium is limited. We carried out two separate experiments: the first in California (USA), where we verified the capability of Platypedia minor to transmit X. fastidiosa from infected to healthy grapevines; the second in Apulia (South Italy), where we evaluated if Cicada orni collected on infected olive plants were able to trans- mit the bacterium to healthy olives. In California, transmission was not achieved for the 19 grapevines caged each with a group of two to three P. minor; moreover, none of the 19 insects (out of the 47 used for the transmission test) tested by culturing resulted positive for X. fastidiosa. In Italy, none of the olive recipient plants either caged with groups of three C. orni individuals per plant confined in sleeve cages (55 plants) or placed inside a mesocosm with cicadas free to move among the recipient plants (30 plants), were infected with the bacterium. Moreover, out of the 314 field collected C. orni tested by qPCR, only 4 (1.27%) were positive for the bacterium. Our data suggest that the cicada species we tested likely have no or a negligible role in the natural spread of X. fastidiosa
Seminatural habitats support both grapevine pests and their parasitoids in Mediterranean organic vineyards
No full textSeminatural habitats in agroecosystems support diverse communities of natural enemies and are expected to promote biological control in crop fields. However, complex landscapes may also support agricultural pests, with undesirable outcomes for crop production. Here, we monitored populations of leafhopper pests and their egg parasitoids in two habitats: vineyards and seminatural habitats. Our results showed that the composition of the agricultural matrix strongly influences the spatio-temporal dynamics of leafhoppers and their egg parasitoids. Specifically, seminatural habitat cover in the landscape was positively correlated to leafhopper abundance in vineyards and to parasitoid abundance in both habitats. Vineyard cover in the landscape instead influenced leafhopper abundance in seminatural habitats. Our analyses indicate that seminatural habitats might be a greater source of leafhoppers than of their egg parasitoids in Mediterranean agroecosystems, with negative implication for their sustainable control in organic vineyards. Although seminatural habitats play a fundamental role in supporting farmland diversity and ecosystem service provision, they might not contribute to mitigate leafhopper impact in Mediterranean vineyards
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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